/* This file is part of GNUnet. Copyright (C) 2011, 2017 GNUnet e.V. GNUnet is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. GNUnet is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more details. You should have received a copy of the GNU Affero General Public License along with this program. If not, see . SPDX-License-Identifier: AGPL3.0-or-later */ /** * @file cadet/cadet_api.c * @brief cadet api: client implementation of cadet service * @author Bartlomiej Polot * @author Christian Grothoff */ #include "platform.h" #include "gnunet_util_lib.h" #include "gnunet_constants.h" #include "gnunet_cadet_service.h" #include "cadet.h" #include "cadet_protocol.h" #define LOG(kind,...) GNUNET_log_from (kind, "cadet-api",__VA_ARGS__) /** * Opaque handle to the service. */ struct GNUNET_CADET_Handle { /** * Message queue. */ struct GNUNET_MQ_Handle *mq; /** * Ports open. */ struct GNUNET_CONTAINER_MultiHashMap *ports; /** * Channels open. */ struct GNUNET_CONTAINER_MultiHashMap32 *channels; /** * child of the next channel to create (to avoid reusing IDs often) */ struct GNUNET_CADET_ClientChannelNumber next_ccn; /** * Configuration given by the client, in case of reconnection */ const struct GNUNET_CONFIGURATION_Handle *cfg; /** * Task for trying to reconnect. */ struct GNUNET_SCHEDULER_Task *reconnect_task; /** * Time to the next reconnect in case one reconnect fails */ struct GNUNET_TIME_Relative reconnect_time; }; /** * Opaque handle to a channel. */ struct GNUNET_CADET_Channel { /** * Other end of the channel. */ struct GNUNET_PeerIdentity peer; /** * Handle to the cadet this channel belongs to */ struct GNUNET_CADET_Handle *cadet; /** * Channel's port, if incoming. */ struct GNUNET_CADET_Port *incoming_port; /** * Any data the caller wants to put in here, used for the * various callbacks (@e disconnects, @e window_changes, handlers). */ void *ctx; /** * Message Queue for the channel (which we are implementing). */ struct GNUNET_MQ_Handle *mq; /** * Task to allow mq to send more traffic. */ struct GNUNET_SCHEDULER_Task *mq_cont; /** * Pending envelope with a message to be transmitted to the * service as soon as we are allowed to. Should only be * non-NULL if @e allow_send is 0. */ struct GNUNET_MQ_Envelope *pending_env; /** * Window change handler. */ GNUNET_CADET_WindowSizeEventHandler window_changes; /** * Disconnect handler. */ GNUNET_CADET_DisconnectEventHandler disconnects; /** * Local ID of the channel, #GNUNET_CADET_LOCAL_CHANNEL_ID_CLI bit is set if outbound. */ struct GNUNET_CADET_ClientChannelNumber ccn; /** * Channel options: reliability, etc. */ enum GNUNET_CADET_ChannelOption options; /** * How many messages are we allowed to send to the service right now? */ unsigned int allow_send; }; /** * Opaque handle to a port. */ struct GNUNET_CADET_Port { /** * Port "number" */ struct GNUNET_HashCode id; /** * Handle to the CADET session this port belongs to. */ struct GNUNET_CADET_Handle *cadet; /** * Closure for @a handler. */ void *cls; /** * Handler for incoming channels on this port */ GNUNET_CADET_ConnectEventHandler connects; /** * Closure for @ref connects */ void *connects_cls; /** * Window size change handler. */ GNUNET_CADET_WindowSizeEventHandler window_changes; /** * Handler called when an incoming channel is destroyed. */ GNUNET_CADET_DisconnectEventHandler disconnects; /** * Payload handlers for incoming channels. */ struct GNUNET_MQ_MessageHandler *handlers; }; /** * Find the Port struct for a hash. * * @param h CADET handle. * @param hash HashCode for the port number. * @return The port handle if known, NULL otherwise. */ static struct GNUNET_CADET_Port * find_port (const struct GNUNET_CADET_Handle *h, const struct GNUNET_HashCode *hash) { return GNUNET_CONTAINER_multihashmap_get (h->ports, hash); } /** * Get the channel handler for the channel specified by id from the given handle * * @param h Cadet handle * @param ccn ID of the wanted channel * @return handle to the required channel or NULL if not found */ static struct GNUNET_CADET_Channel * find_channel (struct GNUNET_CADET_Handle *h, struct GNUNET_CADET_ClientChannelNumber ccn) { return GNUNET_CONTAINER_multihashmap32_get (h->channels, ntohl (ccn.channel_of_client)); } /** * Create a new channel and insert it in the channel list of the cadet handle * * @param h Cadet handle * @param ccnp pointer to desired ccn of the channel, NULL to assign one automatically. * @return Handle to the created channel. */ static struct GNUNET_CADET_Channel * create_channel (struct GNUNET_CADET_Handle *h, const struct GNUNET_CADET_ClientChannelNumber *ccnp) { struct GNUNET_CADET_Channel *ch; struct GNUNET_CADET_ClientChannelNumber ccn; ch = GNUNET_new (struct GNUNET_CADET_Channel); ch->cadet = h; if (NULL == ccnp) { while (NULL != find_channel (h, h->next_ccn)) h->next_ccn.channel_of_client = htonl (GNUNET_CADET_LOCAL_CHANNEL_ID_CLI | (1 + ntohl (h->next_ccn.channel_of_client))); ccn = h->next_ccn; } else { ccn = *ccnp; } ch->ccn = ccn; GNUNET_assert (GNUNET_OK == GNUNET_CONTAINER_multihashmap32_put (h->channels, ntohl (ch->ccn.channel_of_client), ch, GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY)); return ch; } /** * Destroy the specified channel. * - Destroys all peers, calling the disconnect callback on each if needed * - Cancels all outgoing traffic for that channel, calling respective notifys * - Calls cleaner if channel was inbound * - Frees all memory used * * @param ch Pointer to the channel. * @param call_cleaner Whether to call the cleaner handler. */ static void destroy_channel (struct GNUNET_CADET_Channel *ch) { struct GNUNET_CADET_Handle *h = ch->cadet; LOG (GNUNET_ERROR_TYPE_DEBUG, "Destroying channel %X of %p\n", htonl (ch->ccn.channel_of_client), h); GNUNET_assert (GNUNET_YES == GNUNET_CONTAINER_multihashmap32_remove (h->channels, ntohl (ch->ccn.channel_of_client), ch)); if (NULL != ch->mq_cont) { GNUNET_SCHEDULER_cancel (ch->mq_cont); ch->mq_cont = NULL; } /* signal channel destruction */ if (NULL != ch->disconnects) ch->disconnects (ch->ctx, ch); if (NULL != ch->pending_env) GNUNET_MQ_discard (ch->pending_env); GNUNET_MQ_destroy (ch->mq); GNUNET_free (ch); } /** * Reconnect to the service, retransmit all infomation to try to restore the * original state. * * @param h handle to the cadet */ static void reconnect (struct GNUNET_CADET_Handle *h); /** * Function called during #reconnect_cbk() to (re)open * all ports that are still open. * * @param cls the `struct GNUNET_CADET_Handle` * @param id port ID * @param value a `struct GNUNET_CADET_Channel` to open * @return #GNUNET_OK (continue to iterate) */ static int open_port_cb (void *cls, const struct GNUNET_HashCode *id, void *value) { struct GNUNET_CADET_Handle *h = cls; struct GNUNET_CADET_Port *port = value; struct GNUNET_CADET_PortMessage *msg; struct GNUNET_MQ_Envelope *env; (void) id; env = GNUNET_MQ_msg (msg, GNUNET_MESSAGE_TYPE_CADET_LOCAL_PORT_OPEN); msg->port = port->id; GNUNET_MQ_send (h->mq, env); return GNUNET_OK; } /** * Reconnect callback: tries to reconnect again after a failer previous * reconnecttion * * @param cls closure (cadet handle) */ static void reconnect_cbk (void *cls) { struct GNUNET_CADET_Handle *h = cls; h->reconnect_task = NULL; h->reconnect_time = GNUNET_TIME_STD_BACKOFF (h->reconnect_time); reconnect (h); GNUNET_CONTAINER_multihashmap_iterate (h->ports, &open_port_cb, h); } /** * Notify the application about a change in the window size (if needed). * * @param ch Channel to notify about. */ static void notify_window_size (struct GNUNET_CADET_Channel *ch) { if (NULL != ch->window_changes) ch->window_changes (ch->ctx, ch, /* FIXME: remove 'ch'? */ ch->allow_send); } /** * Transmit the next message from our queue. * * @param cls Closure (channel whose mq to activate). */ static void cadet_mq_send_now (void *cls) { struct GNUNET_CADET_Channel *ch = cls; struct GNUNET_MQ_Envelope *env = ch->pending_env; ch->mq_cont = NULL; if (0 == ch->allow_send) { /* how did we get here? */ GNUNET_break (0); return; } if (NULL == env) { /* how did we get here? */ GNUNET_break (0); return; } ch->allow_send--; ch->pending_env = NULL; GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Sending message on channel %s to CADET, new window size is %u\n", GNUNET_i2s (&ch->peer), ch->allow_send); GNUNET_MQ_send (ch->cadet->mq, env); GNUNET_MQ_impl_send_continue (ch->mq); } /** * Implement sending functionality of a message queue for * us sending messages to a peer. * * Encapsulates the payload message in a #GNUNET_CADET_LocalData message * in order to label the message with the channel ID and send the * encapsulated message to the service. * * @param mq the message queue * @param msg the message to send * @param impl_state state of the implementation */ static void cadet_mq_send_impl (struct GNUNET_MQ_Handle *mq, const struct GNUNET_MessageHeader *msg, void *impl_state) { struct GNUNET_CADET_Channel *ch = impl_state; struct GNUNET_CADET_Handle *h = ch->cadet; uint16_t msize; struct GNUNET_MQ_Envelope *env; struct GNUNET_CADET_LocalData *cadet_msg = NULL; if (NULL == h->mq) { /* We're currently reconnecting, pretend this worked */ GNUNET_MQ_impl_send_continue (mq); return; } /* check message size for sanity */ msize = ntohs (msg->size); if (msize > GNUNET_CONSTANTS_MAX_CADET_MESSAGE_SIZE) { GNUNET_break (0); GNUNET_MQ_impl_send_continue (mq); return; } env = GNUNET_MQ_msg_nested_mh (cadet_msg, GNUNET_MESSAGE_TYPE_CADET_LOCAL_DATA, msg); cadet_msg->ccn = ch->ccn; GNUNET_assert (NULL == ch->pending_env); ch->pending_env = env; if (0 < ch->allow_send) ch->mq_cont = GNUNET_SCHEDULER_add_now (&cadet_mq_send_now, ch); } /** * Handle destruction of a message queue. Implementations must not * free @a mq, but should take care of @a impl_state. * * @param mq the message queue to destroy * @param impl_state state of the implementation */ static void cadet_mq_destroy_impl (struct GNUNET_MQ_Handle *mq, void *impl_state) { struct GNUNET_CADET_Channel *ch = impl_state; GNUNET_assert (mq == ch->mq); ch->mq = NULL; } /** * We had an error processing a message we forwarded from a peer to * the CADET service. We should just complain about it but otherwise * continue processing. * * @param cls closure with our `struct GNUNET_CADET_Channel` * @param error error code */ static void cadet_mq_error_handler (void *cls, enum GNUNET_MQ_Error error) { struct GNUNET_CADET_Channel *ch = cls; if (GNUNET_MQ_ERROR_NO_MATCH == error) { /* Got a message we did not understand, still try to continue! */ GNUNET_break_op (0); GNUNET_CADET_receive_done (ch); } else { GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "MQ error in communication with CADET: %d\n", error); if (NULL != ch->disconnects) ch->disconnects (ch->ctx, ch); GNUNET_CADET_channel_destroy (ch); } } /** * Implementation function that cancels the currently sent message. * Should basically undo whatever #mq_send_impl() did. * * @param mq message queue * @param impl_state state specific to the implementation */ static void cadet_mq_cancel_impl (struct GNUNET_MQ_Handle *mq, void *impl_state) { struct GNUNET_CADET_Channel *ch = impl_state; (void) mq; GNUNET_assert (NULL != ch->pending_env); GNUNET_MQ_discard (ch->pending_env); ch->pending_env = NULL; if (NULL != ch->mq_cont) { GNUNET_SCHEDULER_cancel (ch->mq_cont); ch->mq_cont = NULL; } } /** * Process the new channel notification and add it to the channels in the handle * * @param h The cadet handle * @param msg A message with the details of the new incoming channel */ static void handle_channel_created (void *cls, const struct GNUNET_CADET_LocalChannelCreateMessage *msg) { struct GNUNET_CADET_Handle *h = cls; struct GNUNET_CADET_Channel *ch; struct GNUNET_CADET_Port *port; const struct GNUNET_HashCode *port_number; struct GNUNET_CADET_ClientChannelNumber ccn; ccn = msg->ccn; port_number = &msg->port; if (ntohl (ccn.channel_of_client) >= GNUNET_CADET_LOCAL_CHANNEL_ID_CLI) { GNUNET_break (0); return; } port = find_port (h, port_number); if (NULL == port) { /* We could have closed the port but the service didn't know about it yet * This is not an error. */ struct GNUNET_CADET_LocalChannelDestroyMessage *d_msg; struct GNUNET_MQ_Envelope *env; LOG (GNUNET_ERROR_TYPE_DEBUG, "No handler for incoming channel %X (on port %s, recently closed?)\n", ntohl (ccn.channel_of_client), GNUNET_h2s (port_number)); env = GNUNET_MQ_msg (d_msg, GNUNET_MESSAGE_TYPE_CADET_LOCAL_CHANNEL_DESTROY); d_msg->ccn = msg->ccn; GNUNET_MQ_send (h->mq, env); return; } ch = create_channel (h, &ccn); ch->peer = msg->peer; ch->incoming_port = port; ch->options = ntohl (msg->opt); LOG (GNUNET_ERROR_TYPE_DEBUG, "Creating incoming channel %X [%s] %p\n", ntohl (ccn.channel_of_client), GNUNET_h2s (port_number), ch); GNUNET_assert (NULL != port->connects); ch->window_changes = port->window_changes; ch->disconnects = port->disconnects; ch->mq = GNUNET_MQ_queue_for_callbacks (&cadet_mq_send_impl, &cadet_mq_destroy_impl, &cadet_mq_cancel_impl, ch, port->handlers, &cadet_mq_error_handler, ch); ch->ctx = port->connects (port->cls, ch, &msg->peer); GNUNET_MQ_set_handlers_closure (ch->mq, ch->ctx); } /** * Process the channel destroy notification and free associated resources * * @param h The cadet handle * @param msg A message with the details of the channel being destroyed */ static void handle_channel_destroy (void *cls, const struct GNUNET_CADET_LocalChannelDestroyMessage *msg) { struct GNUNET_CADET_Handle *h = cls; struct GNUNET_CADET_Channel *ch; ch = find_channel (h, msg->ccn); if (NULL == ch) { LOG (GNUNET_ERROR_TYPE_DEBUG, "Received channel destroy for unknown channel %X from CADET service (recently close?)\n", ntohl (msg->ccn.channel_of_client)); return; } LOG (GNUNET_ERROR_TYPE_DEBUG, "Received channel destroy for channel %X from CADET service\n", ntohl (msg->ccn.channel_of_client)); destroy_channel (ch); } /** * Check that message received from CADET service is well-formed. * * @param cls the `struct GNUNET_CADET_Handle` * @param message the message we got * @return #GNUNET_OK if the message is well-formed, * #GNUNET_SYSERR otherwise */ static int check_local_data (void *cls, const struct GNUNET_CADET_LocalData *message) { uint16_t size; (void) cls; size = ntohs (message->header.size); if (sizeof (*message) + sizeof (struct GNUNET_MessageHeader) > size) { GNUNET_break (0); return GNUNET_SYSERR; } return GNUNET_OK; } /** * Process the incoming data packets, call appropriate handlers. * * @param h The cadet handle * @param message A message encapsulating the data */ static void handle_local_data (void *cls, const struct GNUNET_CADET_LocalData *message) { struct GNUNET_CADET_Handle *h = cls; const struct GNUNET_MessageHeader *payload; struct GNUNET_CADET_Channel *ch; uint16_t type; int fwd; ch = find_channel (h, message->ccn); if (NULL == ch) { LOG (GNUNET_ERROR_TYPE_DEBUG, "Unknown channel %X for incoming data (recently closed?)\n", ntohl (message->ccn.channel_of_client)); return; } payload = (const struct GNUNET_MessageHeader *) &message[1]; type = ntohs (payload->type); fwd = ntohl (ch->ccn.channel_of_client) <= GNUNET_CADET_LOCAL_CHANNEL_ID_CLI; LOG (GNUNET_ERROR_TYPE_DEBUG, "Got a %s data on channel %s [%X] of type %u\n", fwd ? "FWD" : "BWD", GNUNET_i2s (&ch->peer), ntohl (message->ccn.channel_of_client), type); GNUNET_MQ_inject_message (ch->mq, payload); } /** * Process a local ACK message, enabling the client to send * more data to the service. * * @param h Cadet handle. * @param message Message itself. */ static void handle_local_ack (void *cls, const struct GNUNET_CADET_LocalAck *message) { struct GNUNET_CADET_Handle *h = cls; struct GNUNET_CADET_Channel *ch; ch = find_channel (h, message->ccn); if (NULL == ch) { LOG (GNUNET_ERROR_TYPE_DEBUG, "ACK on unknown channel %X\n", ntohl (message->ccn.channel_of_client)); return; } ch->allow_send++; LOG (GNUNET_ERROR_TYPE_DEBUG, "Got an ACK on mq channel %X (peer %s); new window size is %u!\n", ntohl (ch->ccn.channel_of_client), GNUNET_i2s (&ch->peer), ch->allow_send); if (NULL == ch->pending_env) { LOG (GNUNET_ERROR_TYPE_DEBUG, "Got an ACK on mq channel %X, allow send now %u!\n", ntohl (ch->ccn.channel_of_client), ch->allow_send); notify_window_size (ch); return; } if (NULL != ch->mq_cont) return; /* already working on it! */ ch->mq_cont = GNUNET_SCHEDULER_add_now (&cadet_mq_send_now, ch); } /** * Function called during #GNUNET_CADET_disconnect() to destroy * all channels that are still open. * * @param cls the `struct GNUNET_CADET_Handle` * @param cid chanenl ID * @param value a `struct GNUNET_CADET_Channel` to destroy * @return #GNUNET_OK (continue to iterate) */ static int destroy_channel_cb (void *cls, uint32_t cid, void *value) { /* struct GNUNET_CADET_Handle *handle = cls; */ struct GNUNET_CADET_Channel *ch = value; (void) cls; (void) cid; GNUNET_log (GNUNET_ERROR_TYPE_INFO, "Destroying channel due to GNUNET_CADET_disconnect()\n"); destroy_channel (ch); return GNUNET_OK; } /** * Generic error handler, called with the appropriate error code and * the same closure specified at the creation of the message queue. * Not every message queue implementation supports an error handler. * * @param cls closure, a `struct GNUNET_CORE_Handle *` * @param error error code */ static void handle_mq_error (void *cls, enum GNUNET_MQ_Error error) { struct GNUNET_CADET_Handle *h = cls; GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "MQ ERROR: %u\n", error); GNUNET_CONTAINER_multihashmap32_iterate (h->channels, &destroy_channel_cb, h); GNUNET_MQ_destroy (h->mq); h->mq = NULL; GNUNET_assert (NULL == h->reconnect_task); h->reconnect_task = GNUNET_SCHEDULER_add_delayed (h->reconnect_time, &reconnect_cbk, h); } /** * Reconnect to the service, retransmit all infomation to try to restore the * original state. * * @param h handle to the cadet */ static void reconnect (struct GNUNET_CADET_Handle *h) { struct GNUNET_MQ_MessageHandler handlers[] = { GNUNET_MQ_hd_fixed_size (channel_created, GNUNET_MESSAGE_TYPE_CADET_LOCAL_CHANNEL_CREATE, struct GNUNET_CADET_LocalChannelCreateMessage, h), GNUNET_MQ_hd_fixed_size (channel_destroy, GNUNET_MESSAGE_TYPE_CADET_LOCAL_CHANNEL_DESTROY, struct GNUNET_CADET_LocalChannelDestroyMessage, h), GNUNET_MQ_hd_var_size (local_data, GNUNET_MESSAGE_TYPE_CADET_LOCAL_DATA, struct GNUNET_CADET_LocalData, h), GNUNET_MQ_hd_fixed_size (local_ack, GNUNET_MESSAGE_TYPE_CADET_LOCAL_ACK, struct GNUNET_CADET_LocalAck, h), GNUNET_MQ_handler_end () }; GNUNET_assert (NULL == h->mq); h->mq = GNUNET_CLIENT_connect (h->cfg, "cadet", handlers, &handle_mq_error, h); } /** * Function called during #GNUNET_CADET_disconnect() to destroy * all ports that are still open. * * @param cls the `struct GNUNET_CADET_Handle` * @param id port ID * @param value a `struct GNUNET_CADET_Channel` to destroy * @return #GNUNET_OK (continue to iterate) */ static int destroy_port_cb (void *cls, const struct GNUNET_HashCode *id, void *value) { /* struct GNUNET_CADET_Handle *handle = cls; */ struct GNUNET_CADET_Port *port = value; (void) cls; (void) id; /* This is a warning, the app should have cleanly closed all open ports */ GNUNET_break (0); GNUNET_CADET_close_port (port); return GNUNET_OK; } /** * Disconnect from the cadet service. All channels will be destroyed. All channel * disconnect callbacks will be called on any still connected peers, notifying * about their disconnection. The registered inbound channel cleaner will be * called should any inbound channels still exist. * * @param handle connection to cadet to disconnect */ void GNUNET_CADET_disconnect (struct GNUNET_CADET_Handle *handle) { GNUNET_CONTAINER_multihashmap_iterate (handle->ports, &destroy_port_cb, handle); GNUNET_CONTAINER_multihashmap_destroy (handle->ports); handle->ports = NULL; GNUNET_CONTAINER_multihashmap32_iterate (handle->channels, &destroy_channel_cb, handle); GNUNET_CONTAINER_multihashmap32_destroy (handle->channels); handle->channels = NULL; if (NULL != handle->mq) { GNUNET_MQ_destroy (handle->mq); handle->mq = NULL; } if (NULL != handle->reconnect_task) { GNUNET_SCHEDULER_cancel (handle->reconnect_task); handle->reconnect_task = NULL; } GNUNET_free (handle); } /** * Close a port opened with @a GNUNET_CADET_open_port(). * The @a new_channel callback will no longer be called. * * @param p Port handle. */ void GNUNET_CADET_close_port (struct GNUNET_CADET_Port *p) { GNUNET_assert (GNUNET_YES == GNUNET_CONTAINER_multihashmap_remove (p->cadet->ports, &p->id, p)); if (NULL != p->cadet->mq) { struct GNUNET_CADET_PortMessage *msg; struct GNUNET_MQ_Envelope *env; env = GNUNET_MQ_msg (msg, GNUNET_MESSAGE_TYPE_CADET_LOCAL_PORT_CLOSE); msg->port = p->id; GNUNET_MQ_send (p->cadet->mq, env); } GNUNET_free_non_null (p->handlers); GNUNET_free (p); } /** * Destroy an existing channel. * * The existing end callback for the channel will NOT be called. * Any pending outgoing messages will be sent but no incoming messages will be * accepted and no data callbacks will be called. * * @param channel Channel handle, becomes invalid after this call. */ void GNUNET_CADET_channel_destroy (struct GNUNET_CADET_Channel *channel) { struct GNUNET_CADET_Handle *h = channel->cadet; struct GNUNET_CADET_LocalChannelDestroyMessage *msg; struct GNUNET_MQ_Envelope *env; if (NULL != h->mq) { env = GNUNET_MQ_msg (msg, GNUNET_MESSAGE_TYPE_CADET_LOCAL_CHANNEL_DESTROY); msg->ccn = channel->ccn; GNUNET_MQ_send (h->mq, env); } GNUNET_log (GNUNET_ERROR_TYPE_INFO, "Destroying channel due to GNUNET_CADET_channel_destroy()\n"); channel->disconnects = NULL; destroy_channel (channel); } /** * Get information about a channel. * * @param channel Channel handle. * @param option Query (GNUNET_CADET_OPTION_*). * @param ... dependant on option, currently not used * * @return Union with an answer to the query. */ const union GNUNET_CADET_ChannelInfo * GNUNET_CADET_channel_get_info (struct GNUNET_CADET_Channel *channel, enum GNUNET_CADET_ChannelOption option, ...) { static int bool_flag; switch (option) { case GNUNET_CADET_OPTION_NOBUFFER: case GNUNET_CADET_OPTION_RELIABLE: case GNUNET_CADET_OPTION_OUT_OF_ORDER: if (0 != (option & channel->options)) bool_flag = GNUNET_YES; else bool_flag = GNUNET_NO; return (const union GNUNET_CADET_ChannelInfo *) &bool_flag; break; case GNUNET_CADET_OPTION_PEER: return (const union GNUNET_CADET_ChannelInfo *) &channel->peer; break; default: GNUNET_break (0); return NULL; } } /** * Send an ack on the channel to confirm the processing of a message. * * @param ch Channel on which to send the ACK. */ void GNUNET_CADET_receive_done (struct GNUNET_CADET_Channel *channel) { struct GNUNET_CADET_LocalAck *msg; struct GNUNET_MQ_Envelope *env; env = GNUNET_MQ_msg (msg, GNUNET_MESSAGE_TYPE_CADET_LOCAL_ACK); LOG (GNUNET_ERROR_TYPE_DEBUG, "Sending ACK on channel %X\n", ntohl (channel->ccn.channel_of_client)); msg->ccn = channel->ccn; GNUNET_MQ_send (channel->cadet->mq, env); } /** * Connect to the MQ-based cadet service. * * @param cfg Configuration to use. * * @return Handle to the cadet service NULL on error. */ struct GNUNET_CADET_Handle * GNUNET_CADET_connect (const struct GNUNET_CONFIGURATION_Handle *cfg) { struct GNUNET_CADET_Handle *h; LOG (GNUNET_ERROR_TYPE_DEBUG, "GNUNET_CADET_connect()\n"); h = GNUNET_new (struct GNUNET_CADET_Handle); h->cfg = cfg; h->ports = GNUNET_CONTAINER_multihashmap_create (4, GNUNET_YES); h->channels = GNUNET_CONTAINER_multihashmap32_create (4); reconnect (h); if (NULL == h->mq) { GNUNET_break (0); GNUNET_CADET_disconnect (h); return NULL; } h->next_ccn.channel_of_client = htonl (GNUNET_CADET_LOCAL_CHANNEL_ID_CLI); return h; } /** * Open a port to receive incomming MQ-based channels. * * @param h CADET handle. * @param port Hash identifying the port. * @param connects Function called when an incoming channel is connected. * @param connects_cls Closure for the @a connects handler. * @param window_changes Function called when the transmit window size changes. * @param disconnects Function called when a channel is disconnected. * @param handlers Callbacks for messages we care about, NULL-terminated. * @return Port handle, NULL if port is in use */ struct GNUNET_CADET_Port * GNUNET_CADET_open_port (struct GNUNET_CADET_Handle *h, const struct GNUNET_HashCode *port, GNUNET_CADET_ConnectEventHandler connects, void * connects_cls, GNUNET_CADET_WindowSizeEventHandler window_changes, GNUNET_CADET_DisconnectEventHandler disconnects, const struct GNUNET_MQ_MessageHandler *handlers) { struct GNUNET_CADET_Port *p; GNUNET_assert (NULL != connects); GNUNET_assert (NULL != disconnects); GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Listening to CADET port %s\n", GNUNET_h2s (port)); p = GNUNET_new (struct GNUNET_CADET_Port); p->cadet = h; p->id = *port; if (GNUNET_OK != GNUNET_CONTAINER_multihashmap_put (h->ports, &p->id, p, GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY)) { GNUNET_free (p); return NULL; } p->connects = connects; p->cls = connects_cls; p->window_changes = window_changes; p->disconnects = disconnects; p->handlers = GNUNET_MQ_copy_handlers (handlers); GNUNET_assert (GNUNET_OK == open_port_cb (h, &p->id, p)); return p; } /** * Create a new channel towards a remote peer. * * If the destination port is not open by any peer or the destination peer * does not accept the channel, #GNUNET_CADET_ChannelEndHandler will be called * for this channel. * * @param h CADET handle. * @param channel_cls Closure for the channel. It's given to: * - The disconnect handler @a disconnects * - Each message type callback in @a handlers * @param destination Peer identity the channel should go to. * @param port Identification of the destination port. * @param options CadetOption flag field, with all desired option bits set to 1. * @param window_changes Function called when the transmit window size changes. * @param disconnects Function called when the channel is disconnected. * @param handlers Callbacks for messages we care about, NULL-terminated. * @return Handle to the channel. */ struct GNUNET_CADET_Channel * GNUNET_CADET_channel_create (struct GNUNET_CADET_Handle *h, void *channel_cls, const struct GNUNET_PeerIdentity *destination, const struct GNUNET_HashCode *port, enum GNUNET_CADET_ChannelOption options, GNUNET_CADET_WindowSizeEventHandler window_changes, GNUNET_CADET_DisconnectEventHandler disconnects, const struct GNUNET_MQ_MessageHandler *handlers) { struct GNUNET_CADET_Channel *ch; struct GNUNET_CADET_LocalChannelCreateMessage *msg; struct GNUNET_MQ_Envelope *env; GNUNET_assert (NULL != disconnects); GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Creating channel to peer %s at port %s\n", GNUNET_i2s (destination), GNUNET_h2s (port)); ch = create_channel (h, NULL); ch->ctx = channel_cls; ch->peer = *destination; ch->options = options; ch->window_changes = window_changes; ch->disconnects = disconnects; /* Create MQ for channel */ ch->mq = GNUNET_MQ_queue_for_callbacks (&cadet_mq_send_impl, &cadet_mq_destroy_impl, &cadet_mq_cancel_impl, ch, handlers, &cadet_mq_error_handler, ch); GNUNET_MQ_set_handlers_closure (ch->mq, channel_cls); /* Request channel creation to service */ env = GNUNET_MQ_msg (msg, GNUNET_MESSAGE_TYPE_CADET_LOCAL_CHANNEL_CREATE); msg->ccn = ch->ccn; msg->port = *port; msg->peer = *destination; msg->opt = htonl (options); GNUNET_MQ_send (h->mq, env); return ch; } /** * Obtain the message queue for a connected peer. * * @param channel The channel handle from which to get the MQ. * * @return NULL if @a channel is not yet connected. */ struct GNUNET_MQ_Handle * GNUNET_CADET_get_mq (const struct GNUNET_CADET_Channel *channel) { return channel->mq; } /* end of cadet_api.c */